title: One minute, sub-one-watt photothermal tumor ablation using porphysomes, intrinsic multifunctional nanovesicles.
abstract: We recently developed porphysomes as intrinsically multifunctional nanovesicles. A photosensitizer, pyropheophorbide α, was conjugated to a phospholipid and then self-assembled to liposome-like spherical vesicles. Due to the extremely high density of porphyrin in the porphyrin-lipid bilayer, porphysomes generated large extinction coefficients, structure-dependent fluorescence self-quenching, and excellent photothermal efficacy. In our formulation, porphysomes were synthesized using high pressure extrusion, and displayed a mean particle size around 120 nm. Twenty-four hr post-intravenous injection of porphysomes, the local temperature of the tumor increased from 30 °C to 62 °C rapidly upon one minute exposure of 750 mW (1.18 W/cm(2)), 671 nm laser irradiation. Following the complete thermal ablation of the tumor, eschars formed and healed within 2 weeks, while in the control groups the tumors continued to grow and all reached the defined end point within 3 weeks. These data show how porphysomes can be used as potent photothermal therapy (PTT) agents.
authors.affiliation: Department of Pharmaceutical Sciences, University of Toronto.
authors.forename: Cheng S
authors.initials: CS
authors.lastname: Jin
authors.forename: Jonathan F
authors.initials: JF
authors.lastname: Lovell
authors.forename: Gang
authors.initials: G
authors.lastname: Zheng
mesh_terms: D055011:Ablation Techniques / Q000295:instrumentation / Q000379:methods*; D000818:Animals; D002734:Chlorophyll / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D006979:Hyperthermia, Induced / Q000379:methods; D007624:KB Cells; D051379:Mice; D008819:Mice, Nude; D053758:Nanoparticles / Q000008:administration & dosage* / Q000737:chemistry*; D010743:Phospholipids / Q000737:chemistry / Q000494:pharmacology; D017319:Photosensitizing Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D010789:Phototherapy / Q000379:methods; D023041:Xenograft Model Antitumor Assays
chemical_list: D010743:Phospholipids; D017319:Photosensitizing Agents; D002734:Chlorophyll; C040298:pyropheophorbide a